reactos/ntoskrnl/ob/wait.c

   1 /*
   2  * COPYRIGHT:          See COPYING in the top level directory
   3  * PROJECT:            ReactOS kernel
   4  * FILE:               ntoskrnl/ob/wait.c
   5  * PURPOSE:            Handles Waiting on Objects
   6  *
   7  * PROGRAMMERS:        Alex Ionescu (alex@relsoft.net)
   8  *                     David Welch (welch@mcmail.com)
   9  */
  10
  11 /* INCLUDES ******************************************************************/
  12
  13 #include <ntoskrnl.h>
  14 #define NDEBUG
  15 #include <internal/debug.h>
  16
  17 #define TAG_WAIT TAG('W', 'a', 'i', 't')
  18
  19 /* FUNCTIONS *****************************************************************/
  20
  21 NTSTATUS
  22 STDCALL
  23 NtWaitForMultipleObjects(IN ULONG ObjectCount,
  24                          IN PHANDLE HandleArray,
  25                          IN WAIT_TYPE WaitType,
  26                          IN BOOLEAN Alertable,
  27                          IN PLARGE_INTEGER TimeOut  OPTIONAL)
  28 {
  29     PKWAIT_BLOCK WaitBlockArray = NULL;
  30     HANDLE Handles[MAXIMUM_WAIT_OBJECTS];
  31     PVOID Objects[MAXIMUM_WAIT_OBJECTS];
  32     PVOID WaitObjects[MAXIMUM_WAIT_OBJECTS];
  33     ULONG i = 0, ReferencedObjects = 0, j;
  34     KPROCESSOR_MODE PreviousMode = ExGetPreviousMode();
  35     LARGE_INTEGER SafeTimeOut;
  36     BOOLEAN LockInUse;
  37     PHANDLE_TABLE_ENTRY HandleEntry;
  38     POBJECT_HEADER ObjectHeader;
  39     PHANDLE_TABLE HandleTable;
  40     ACCESS_MASK GrantedAccess;
  41     PVOID DefaultObject;
  42     NTSTATUS Status = STATUS_SUCCESS;
  43
  44     DPRINT("NtWaitForMultipleObjects(ObjectCount %lu HandleArray[] %x, Alertable %d, "
  45             "TimeOut %x)\n", ObjectCount, HandleArray, Alertable, TimeOut);
  46
  47     /* Enter a critical region since we'll play with handles */
  48     LockInUse = TRUE;
  49     KeEnterCriticalRegion();
  50
  51     /* Check for valid Object Count */
  52     if ((ObjectCount > MAXIMUM_WAIT_OBJECTS) || !ObjectCount)
  53     {
  54         Status = STATUS_INVALID_PARAMETER_1;
  55         DPRINT1("No object count, or too many objects\n");
  56         goto Quickie;
  57     }
  58
  59     /* Check for valid Wait Type */
  60     if ((WaitType != WaitAll) && (WaitType != WaitAny))
  61     {
  62         Status = STATUS_INVALID_PARAMETER_3;
  63         DPRINT1("Invalid wait type\n");
  64         goto Quickie;
  65     }
  66
  67     /* Capture arguments */
  68     _SEH_TRY
  69     {
  70         if(PreviousMode != KernelMode)
  71         {
  72             ProbeForRead(HandleArray,
  73                          ObjectCount * sizeof(HANDLE),
  74                          sizeof(HANDLE));
  75
  76             if(TimeOut)
  77             {
  78                 /* Make a local copy of the timeout on the stack */
  79                 SafeTimeOut = ProbeForReadLargeInteger(TimeOut);
  80                 TimeOut = &SafeTimeOut;
  81             }
  82         }
  83
  84        /*
  85         * Make a copy so we don't have to guard with SEH later and keep
  86         * track of what objects we referenced if dereferencing pointers
  87         * suddenly fails
  88         */
  89         RtlCopyMemory(Handles,
  90                       HandleArray,
  91                       ObjectCount * sizeof(HANDLE));
  92     }
  93     _SEH_HANDLE
  94     {
  95         Status = _SEH_GetExceptionCode();
  96     }
  97     _SEH_END;
  98
  99     if(!NT_SUCCESS(Status)) goto Quickie;
 100
 101     /* Check if we can use the internal Wait Array */
 102     if (ObjectCount > THREAD_WAIT_OBJECTS)
 103     {
 104         /* Allocate from Pool */
 105         WaitBlockArray = ExAllocatePoolWithTag(NonPagedPool,
 106                                                ObjectCount * sizeof(KWAIT_BLOCK),
 107                                                TAG_WAIT);
 108     }
 109
 110     /* Start the loop */
 111     do
 112     {
 113         /* Use the right Executive Handle */
 114         if(ObIsKernelHandle(Handles[i], PreviousMode))
 115         {
 116             /* Use the System Handle Table and decode */
 117             HandleTable = ObpKernelHandleTable;
 118             Handles[i] = ObKernelHandleToHandle(Handles[i]);
 119         }
 120         else
 121         {
 122             /* Use the Process' Handle table and get the Ex Handle */
 123             HandleTable = PsGetCurrentProcess()->ObjectTable;
 124         }
 125
 126         /* Get a pointer to it */
 127         if (!(HandleEntry = ExMapHandleToPointer(HandleTable, Handles[i])))
 128         {
 129             DPRINT1("Invalid handle\n");
 130             Status = STATUS_INVALID_HANDLE;
 131             goto Quickie;
 132         }
 133
 134         /* Check for synchronize access */
 135         GrantedAccess = HandleEntry->u2.GrantedAccess;
 136         if ((PreviousMode != KernelMode) && (!(GrantedAccess & SYNCHRONIZE)))
 137         {
 138             /* Unlock the entry and fail */
 139             ExUnlockHandleTableEntry(HandleTable, HandleEntry);
 140             Status = STATUS_ACCESS_DENIED;
 141             DPRINT1("Handle doesn't have SYNCH access\n");
 142             goto Quickie;
 143         }
 144
 145         /* Get the Object Header */
 146         ObjectHeader = EX_HTE_TO_HDR(HandleEntry);
 147
 148         /* Get default Object */
 149         DefaultObject = ObjectHeader->Type->DefaultObject;
 150
 151         /* Check if it's the internal offset */
 152         if (IsPointerOffset(DefaultObject))
 153         {
 154             /* Increase reference count */
 155             InterlockedIncrement(&ObjectHeader->PointerCount);
 156             ReferencedObjects++;
 157
 158             /* Save the Object and Wait Object, this is a relative offset */
 159             Objects[i] = &ObjectHeader->Body;
 160             WaitObjects[i] = (PVOID)((ULONG_PTR)&ObjectHeader->Body +
 161                                      (ULONG_PTR)DefaultObject);
 162         }
 163         else
 164         {
 165             /* This is our internal Object */
 166             ReferencedObjects++;
 167             Objects[i] = NULL;
 168             WaitObjects[i] = DefaultObject;
 169         }
 170
 171         /* Unlock the Handle Table Entry */
 172         ExUnlockHandleTableEntry(HandleTable, HandleEntry);
 173
 174         /* Keep looping */
 175         i++;
 176     } while (i < ObjectCount);
 177
 178     /* For a Waitall, we can't have the same object more then once */
 179     if (WaitType == WaitAll)
 180     {
 181         /* Clear the main loop variable */
 182         i = 0;
 183
 184         /* Start the loop */
 185         do
 186         {
 187             /* Check the current and forward object */
 188             for (j = i + 1; j < ObjectCount; j++)
 189             {
 190                 /* Make sure they don't match */
 191                 if (WaitObjects[i] == WaitObjects[j])
 192                 {
 193                     /* Fail */
 194                     Status = STATUS_INVALID_PARAMETER_MIX;
 195                     DPRINT1("Objects duplicated with WaitAll\n");
 196                     goto Quickie;
 197                 }
 198             }
 199
 200             /* Keep looping */
 201             i++;
 202         } while (i < ObjectCount);
 203     }
 204
 205     /* Now we can finally wait. Use SEH since it can raise an exception */
 206     _SEH_TRY
 207     {
 208         /* We're done playing with handles */
 209         LockInUse = FALSE;
 210         KeLeaveCriticalRegion();
 211
 212         /* Do the kernel wait */
 213         Status = KeWaitForMultipleObjects(ObjectCount,
 214                                           WaitObjects,
 215                                           WaitType,
 216                                           UserRequest,
 217                                           PreviousMode,
 218                                           Alertable,
 219                                           TimeOut,
 220                                           WaitBlockArray);
 221     }
 222     _SEH_HANDLE
 223     {
 224         Status = _SEH_GetExceptionCode();
 225     }
 226     _SEH_END;
 227
 228 Quickie:
 229     /* First derefence */
 230     while (ReferencedObjects)
 231     {
 232         ReferencedObjects--;
 233         if (Objects[ReferencedObjects])
 234         {
 235             ObDereferenceObject(Objects[ReferencedObjects]);
 236         }
 237     }
 238
 239     /* Free wait block array */
 240     if (WaitBlockArray) ExFreePool(WaitBlockArray);
 241
 242     /* Re-enable APCs if needed */
 243     if (LockInUse) KeLeaveCriticalRegion();
 244
 245     /* Return status */
 246     DPRINT("Returning: %x\n", Status);
 247     return Status;
 248 }
 249
 250 /*
 251  * @implemented
 252  */
 253 NTSTATUS
 254 STDCALL
 255 NtWaitForSingleObject(IN HANDLE ObjectHandle,
 256                       IN BOOLEAN Alertable,
 257                       IN PLARGE_INTEGER TimeOut  OPTIONAL)
 258 {
 259     PVOID Object, WaitableObject;
 260     KPROCESSOR_MODE PreviousMode = ExGetPreviousMode();
 261     LARGE_INTEGER SafeTimeOut;
 262     NTSTATUS Status = STATUS_SUCCESS;
 263
 264     DPRINT("NtWaitForSingleObject(ObjectHandle %x, Alertable %d, TimeOut %x)\n",
 265             ObjectHandle,Alertable,TimeOut);
 266
 267     /* Capture timeout */
 268     if(TimeOut && PreviousMode != KernelMode)
 269     {
 270         _SEH_TRY
 271         {
 272             /* Make a copy on the stack */
 273             SafeTimeOut = ProbeForReadLargeInteger(TimeOut);
 274             TimeOut = &SafeTimeOut;
 275         }
 276         _SEH_HANDLE
 277         {
 278             Status = _SEH_GetExceptionCode();
 279         }
 280         _SEH_END;
 281
 282         if(!NT_SUCCESS(Status)) return Status;
 283     }
 284
 285     /* Get the Object */
 286     Status = ObReferenceObjectByHandle(ObjectHandle,
 287                                        SYNCHRONIZE,
 288                                        NULL,
 289                                        PreviousMode,
 290                                        &Object,
 291                                        NULL);
 292     if (NT_SUCCESS(Status))
 293     {
 294         /* Get the Waitable Object */
 295         WaitableObject = BODY_TO_HEADER(Object)->Type->DefaultObject;
 296
 297         /* Is it an offset for internal objects? */
 298         if (IsPointerOffset(WaitableObject))
 299         {
 300             /* Turn it into a pointer */
 301             WaitableObject = (PVOID)((ULONG_PTR)Object +
 302                                      (ULONG_PTR)WaitableObject);
 303         }
 304
 305         /* Now wait. Also SEH this since it can also raise an exception */
 306         _SEH_TRY
 307         {
 308             Status = KeWaitForSingleObject(WaitableObject,
 309                                            UserRequest,
 310                                            PreviousMode,
 311                                            Alertable,
 312                                            TimeOut);
 313         }
 314         _SEH_HANDLE
 315         {
 316             Status = _SEH_GetExceptionCode();
 317         }
 318         _SEH_END;
 319
 320         /* Dereference the Object */
 321         ObDereferenceObject(Object);
 322     }
 323
 324     /* Return the status */
 325     return Status;
 326 }
 327
 328 NTSTATUS
 329 STDCALL
 330 NtSignalAndWaitForSingleObject(IN HANDLE ObjectHandleToSignal,
 331                                IN HANDLE WaitableObjectHandle,
 332                                IN BOOLEAN Alertable,
 333                                IN PLARGE_INTEGER TimeOut  OPTIONAL)
 334 {
 335     KPROCESSOR_MODE PreviousMode = ExGetPreviousMode();
 336     POBJECT_TYPE Type;
 337     PVOID SignalObj;
 338     PVOID WaitObj;
 339     PVOID WaitableObject;
 340     LARGE_INTEGER SafeTimeOut;
 341     OBJECT_HANDLE_INFORMATION HandleInfo;
 342     NTSTATUS Status = STATUS_SUCCESS;
 343
 344     /* Capture timeout */
 345     DPRINT("NtSignalAndWaitForSingleObject\n");
 346     if(TimeOut && PreviousMode != KernelMode)
 347     {
 348         _SEH_TRY
 349         {
 350             /* Make a copy on the stack */
 351             SafeTimeOut = ProbeForReadLargeInteger(TimeOut);
 352             TimeOut = &SafeTimeOut;
 353         }
 354         _SEH_HANDLE
 355         {
 356             Status = _SEH_GetExceptionCode();
 357         }
 358         _SEH_END;
 359
 360         if(!NT_SUCCESS(Status)) return Status;
 361     }
 362
 363     /* Start by getting the signal object*/
 364     Status = ObReferenceObjectByHandle(ObjectHandleToSignal,
 365                                        0,
 366                                        NULL,
 367                                        PreviousMode,
 368                                        &SignalObj,
 369                                        &HandleInfo);
 370     if (!NT_SUCCESS(Status))
 371     {
 372         return Status;
 373     }
 374
 375     /* Now get the wait object */
 376     Status = ObReferenceObjectByHandle(WaitableObjectHandle,
 377                                        SYNCHRONIZE,
 378                                        NULL,
 379                                        PreviousMode,
 380                                        &WaitObj,
 381                                        NULL);
 382     if (!NT_SUCCESS(Status))
 383     {
 384         ObDereferenceObject(SignalObj);
 385         return Status;
 386     }
 387
 388     /* Get the real waitable object */
 389     WaitableObject = BODY_TO_HEADER(WaitObj)->Type->DefaultObject;
 390
 391     /* Handle internal offset */
 392     if (IsPointerOffset(WaitableObject))
 393     {
 394         /* Get real pointer */
 395         WaitableObject = (PVOID)((ULONG_PTR)WaitObj +
 396                                  (ULONG_PTR)WaitableObject);
 397     }
 398
 399     /* Check Signal Object Type */
 400     Type = BODY_TO_HEADER(WaitObj)->Type;
 401     if (Type == ExEventObjectType)
 402     {
 403         /* Set the Event */
 404         /* FIXME: Check permissions */
 405         KeSetEvent(SignalObj, EVENT_INCREMENT, TRUE);
 406     }
 407     else if (Type == ExMutantObjectType)
 408     {
 409         /* Release the Mutant. This can raise an exception*/
 410         _SEH_TRY
 411         {
 412             KeReleaseMutant(SignalObj, MUTANT_INCREMENT, FALSE, TRUE);
 413         }
 414         _SEH_HANDLE
 415         {
 416             Status = _SEH_GetExceptionCode();
 417             goto Quickie;
 418         }
 419         _SEH_END;
 420     }
 421     else if (Type == ExSemaphoreObjectType)
 422     {
 423         /* Release the Semaphore. This can raise an exception*/
 424         /* FIXME: Check permissions */
 425         _SEH_TRY
 426         {
 427             KeReleaseSemaphore(SignalObj, SEMAPHORE_INCREMENT, 1, TRUE);
 428         }
 429         _SEH_HANDLE
 430         {
 431             Status = _SEH_GetExceptionCode();
 432             goto Quickie;
 433         }
 434         _SEH_END;
 435     }
 436     else
 437     {
 438         Status = STATUS_OBJECT_TYPE_MISMATCH;
 439         DPRINT1("Waiting on invalid object type\n");
 440         goto Quickie;
 441     }
 442
 443     /* Now wait. Also SEH this since it can also raise an exception */
 444     _SEH_TRY
 445     {
 446         Status = KeWaitForSingleObject(WaitableObject,
 447                                        UserRequest,
 448                                        PreviousMode,
 449                                        Alertable,
 450                                        TimeOut);
 451     }
 452     _SEH_HANDLE
 453     {
 454         Status = _SEH_GetExceptionCode();
 455     }
 456     _SEH_END;
 457
 458     /* We're done here */
 459 Quickie:
 460     ObDereferenceObject(SignalObj);
 461     ObDereferenceObject(WaitObj);
 462     return Status;
 463 }
 464
 465 /* EOF */